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Topic: top up a batch (Read 4293 times)

I've done half a dozen all grain 5gal batches (BIAB) and have yet to hit my final volume. My most recent batch is an abbey ale that, once again, is going to finish ageing at 4 to 4.5 gal. Has anyone topped off a batch at bottling time and if so what do i need to watch out for? My OG was 1.070 so i have plenty of room to tweak my volume if it's possible and/or recommended.

I shoot for a specific gravity (not volume) into the fermenter. To get there I target a pre-boil gravity and adjust it up or down - by boiling longer/more vigorously or by adding water. I know approximately what my boil-off will be, but I check the gravity three or four times during the boil to allow me to adjust the boil to hit my post-boil gravity. Occasionally I have to adjust my previous adjustments.

The goal is to put something in the neighborhood of 5.5 gal of wort into the fermenter. The gravity is more important to me than the volume.

The changes in volume can sometimes affect the bittering slightly, but I use a lot of late hop additions that can be adjusted easily on the fly with BeerSmith.

I also try to keep in mind that I'm not a commercial brewer and I don't enter competitions; variations and deviations are not going to wreck my cash flow. Although if you are a competition brewer you will certainly be more concerned with gravity than with volume. After all the measuring and recalculating, I relax and have a home brew.

I'm often a half gallon or more shy after the boil, so I top off after chilling. I'll pour everything into a marked plastic bucket, and add water to get my volume up to target. Then it is poured into the glass carboy (after a gravity reading of course) and the yeast is pitched. Pouring slowly, twice, with lots of splashing, has the added bonus of good aeration.

Haven't tried diluting at bottle time. I'd be cautious about adding oxygen. You'll want to minimize splashing and use previously boiled water, since boiling removes oxygen. Other than that I can't think of anything off hand to watch out for.

I mash in a 10gal ss pot with about 4.5 gal of water and 10 to 12 lbs of grain. I then sparge with about 3.5gal in a fermenting bucket. So i get about 6.5 gal at boil. I always figure about a quart boil off and 1/2 gal trub so hope for 5.5 gal in the bucket. Where I'm missing it is in the amount of trub left in the boil pot. In fact I'm ending up with a gal or more so I'm always about half a gallon short in my fermentation bucket.I think if I bump my mash vol up to 5.5 gallons of water I'll be OK, I think.

This was all BIAB and my mash efficiency, according to beersmith, was 64%. ugh.

I use a HERM system. My mash tun is a 10 Gal Igloo water cooler with a bazooka screen. I got a stuck mash once, so I sewed up an ugly BIAB bag to line the tun. Haven't had a stuck mash since. I recirculate my wort through a 25 ft copper coil immersed in an electric brew pot. I use a thermostat on my heating element to keep the water bath at 160 F or step temperature plus 4 to 6 F. (During temperature increases I don't let the bath go over 160 because I'm concerned higher temperatures will degrad the enzymes - that may be overly cautious, but it works well.) Initially I was doing only temperature mashes, but I found I was spending too much time within the Beta amylase temperature range and getting lighter bodied beers when I wanted them full-bodied, so lately I've been heating my mash water to infusion mash strike temperature and adding grain for a single infusion. At the end of the mash I drain the water bath from the boil kettle, run the wort into the kettle and boil. I like the increased maltiness I get from not sparging. I'll occasionally sparge to collect some low-gravity wort for starters.

Generally, if I mash out my efficiency will run in the neighborhood of 70%. I calculate using 65%, so my pre-boil gravity is usually a bit high. If I'm out of time, I'll skip the mash out and get about 65%. Beersmith's dilution tool tells me about how much water to add to approximate the expected pre-boil gravity. I continue to check gravity throughout the boil (using an auto-temperature-correcting refractometer) and adjust the intensity of the boil as I go to approximate my final gravity. If I screw up and have to extend the boil, I'll know enough ahead of time to adjust my late addition hops to still approximate the desired IBUs.

The main point of my system is not the equipment or general brewing procedures, but the frequent gravity measurement and using Beersmith to guide adjustments.

I shoot for gravity, not volume. If I'm a little over, or more often, a little shy, I don't worry about it. I just go with it as is. Sometimes if I use a lot of leaf hops I lose a bit of wort. For that reason if it's got a lot of hops I try to use pellets over leaf.

@durrettdThanks for your reply. Interesting to read your choice of not sparging to increase the maltiness as well your routines to have control on the gravity of your wort.My question: what grain/water ratio do you use for your mash?

Wow, that's way past the 1.25 quart per pound recommended. I'm guessing you don't need the sparge with that ratio. I notice that my sparge water is pretty thin. Maybe I'll try that next.

@chasinreno- I use a ratio 2.75L/Kg. If my calculations are right this should be equal to1.32 in your quarts/pound system.- I agree that durettd uses a ratio that is at least a factor to higher than what I am used to. In addition his procedure is rather different from mine (single infusion/not sparging). However, he is challenging me with his approach

Google "no sparge brewing". You'll get more information than you can read.

My motivation for no sparge is increased "maltiness" (had I been paying attention when I created my username it would have been "MaltMonster"). I loose efficiency, but I gave up saving money on this hobby a long time ago, so just crank the efficiency down to 65% initially and adjust the grain bill up to get the OG you want. With experience you can refine your efficiency, probably up to about 70%.

The logic for using 8 gallons is that my mash tun doesn't quite overflow with 8 gallons plus 14 pounds of grain. It gives me a consistent starting point. My 8 gallons to 10 - 14 pounds translates to 64 pounds of water to 10 - 14 pounds of grain. Translating to the metric system gives about 30.25 liters (a nice logical 30.25 kg) of water to 4.5 - 6.4 kg of grain - a ratio of 6.7:1 to 4.8:1 by weight. Metric measures are so much more logical; maybe some day the US will figure that out. Even the Brits are starting to use it!

Chas:I have a hunch you might be hesitant to let some of the trub etc into your fermenter That stuff settles out during fermentation (and cold break). You might also be losing a lot of hop benefit by not allowing that part of the boil into the carboy. I can't imagine what you would be worried about ... especially with a BIAB brew. If you're having clarity issues, it could have more to do with the time it takes you to get to the right yeast pitching temp.